摘要：
1.创数据库create table Tteacher(t_id int not null ,t_name char(10) not null,t_classesID int not null, t_age int ,t_birth datetime, primary key (t_id), /*主键约束*//*外键约束constraint 约束名称foreign key (外键)references 对应表*/constraint t_classes_teacher foreign key (t_classesID)references Tclasses,)create table Tcla 阅读全文
